GB2358203A - Marine drilling riser system - Google Patents

Marine drilling riser system Download PDF

Info

Publication number
GB2358203A
GB2358203A GB0000831A GB0000831A GB2358203A GB 2358203 A GB2358203 A GB 2358203A GB 0000831 A GB0000831 A GB 0000831A GB 0000831 A GB0000831 A GB 0000831A GB 2358203 A GB2358203 A GB 2358203A
Authority
GB
United Kingdom
Prior art keywords
marine drilling
drilling riser
cables
arrays
marine
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB0000831A
Other versions
GB2358203B (en
GB0000831D0 (en
Inventor
James William Bunce
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to GB0000831A priority Critical patent/GB2358203B/en
Publication of GB0000831D0 publication Critical patent/GB0000831D0/en
Publication of GB2358203A publication Critical patent/GB2358203A/en
Application granted granted Critical
Publication of GB2358203B publication Critical patent/GB2358203B/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH DRILLING; MINING
    • E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B19/00—Handling rods, casings, tubes or the like outside the borehole, e.g. in the derrick; Apparatus for feeding the rods or cables
    • E21B19/002—Handling rods, casings, tubes or the like outside the borehole, e.g. in the derrick; Apparatus for feeding the rods or cables specially adapted for underwater drilling
    • E21B19/004—Handling rods, casings, tubes or the like outside the borehole, e.g. in the derrick; Apparatus for feeding the rods or cables specially adapted for underwater drilling supporting a riser from a drilling or production platform
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH DRILLING; MINING
    • E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
    • E21B17/01—Risers

Abstract

A marine drilling riser 1 has arrays of cables 5,6 disposed vertically over its length to restrain its lateral motion under hydrodynamic loading. Said arrays of cables 5,6 comprise a plurality of horizontally and vertically inclined flexible cables each attached to said marine drilling riser 1 at one end, and at the other end either anchored to the sea floor, or attached to the mooring lines 4 of the drilling unit 2.

Description

1 2358203 MARINE DRILLING RISER This invention relates to marine drilling
risers used for oil and gas exploration from mobile offshore drilling units.
A paramount concern in mobile offshore drilling unit operation is maintaining the marine drilling riser motions within set operational limits. These are principally the upper and lower riser angles, which must be kept to within a few degrees during normal drilling operations. The upper riser angle is usually the easier to control because the riser tensioner system on the chilling unit keeps the riser near vertical at the top, but the lower angle, at the connection to the lower marine riser package on the sea floor, is determined largely by current forces and is therefore more difficult to control.
Controlling the riser motions necessitates stringent measures: 1) to keep the drilling unit within a tight watch radius of a few per cent of water depth, 2) maintaining high riser top tension, and 3) minimising riser inwater weight by the use of buoyancy modules attached to the riser. If the current is very strong it may also be necessary to deploy fairings over the length of the riser to reduce the hydrodynamic drag forces.
The principal limitations of these methods are the capacity of the drilling unit to tension the marine riser and the physical constraints of space on the drilling unit for deployment of buoyancy modules and/or fairings. The disadvantages are the very high costs and the length of time required deploying and recovering the equipment.
The present invention relates to a method of controlling marine drilling riser motions that is more effective, simpler to deploy and cheaper than the methods used at present.
Thus, according to the present invention there is provided a marine drilling riser whose lateral motion under hydrodynamic loading is restrained by one or more arrays of cables disposed vertically over its length, wherein said arrays of cables comprise a plurality of horizontally and vertically inclined flexible cables each attached to said marine drilling riser at one end, and at the other end either anchored to the sea floor, or attached to the mooring lines of the drilling unit.
2 Said marine drilling riser may incorporate buoyancy modules and/or fairings of forms already known, and may incorporate vertical guidelines to guide the equipment into position for landing or entry into the well.
Said arrays of cables may include buoyancy elements and/or weights and means of tensioning, for example, cable or chain tensioners of forms already known.
The attachment of said arrays of cables to the marine drilling riser may be by means of clips onto said vertical guidelines.
The attachment of said arrays of cables to the marine drilling riser may include a quick release mechanism that can be activated when the riser has to be retrieved, or if it becomes necessary to disconnect it in severe weather.
Said cables may be steel wire rope or strand, or chains or of lightweight synthetic material construction.
The invention will now be described, by way of examples only, with reference to Figures I and 2 of the attached drawings.
Figure 1 shows a semi -submersible offshore drilling unit.
Figure 2 shows a ship-shaped offshore drilling unit.
Referring to Figure 1, a marine drilling riser I is shown suspended from the drilling unit 2 and attached to the lower marine riser package 3 at the sea floor. Said drilling unit 2 is kept on station by means of mooring lines 4. Lateral motion of the marine drilling riser 1 is restrained by arrays of horizontally and vertically inclined cables 5,6. Some arrays of cables 5 are attached to said marine drilling riser 1 at one end and to said mooring lines 4 at the other end. Some arrays of cables 6 are attached to said marine drilling riser I at one end and, at the other end, are attached to anchors 7 on the sea floor.
3 Referring to Figure 2, a marine drilling riser I is shown suspended from the drilling unit 8 and attached to the lower marine riser package 3 at the sea floor. Said drilling unit 8 is kept on station by means of a dynamic positioning system. Lateral motion of the marine drilling riser 1 is restrained by arrays of horizontally and vertically inclined cables 9 attached to said marine drilling riser I at one end and, at the other end, attached to anchors 7 on the sea floor.
Said anchors 7 may be, for example, clump weights or anchors of other forms already known, and may have pendant lines attached to marker buoys floating at the surface so they can be positioned and located easily.
4

Claims (7)

1. A marine drilling riser whose lateral motion under hydrodynamic loading is restrained by one or more arrays of cables disposed vertically over its length, wherein said arrays of cables comprise a plurality of horizontally and vertically inclined flexible cables each attached to said marine drilling riser at one end, and at the other end either anchored to the sea floor, or attached to the mooring lines of the drilling unit.
2. A marine drilling riser according to claim I that incorporates buoyancy modules and/or fairings of forms already known.
3. A marine drilling riser according to claims 1 and 2 that incorporates vertical guidelines to guide the equipment into position for landing or entry into the well.
4. A marine drilling riser according to claims 1, 2 or 3 wherein said arrays of cables include buoyancy elements and/or weights and means of tensioning, for example, cable or chain tensioners, of forms already known.
5. A marine drilling riser according to any of the preceding claims wherein the attachment of said arrays of cables to the marine drilling riser is by means of clips onto said vertical guidelines.
6. A marine drilling riser according to any of the preceding claims wherein the attachment of said arrays of cables to the marine drilling riser includes a quick release mechanism that can be activated when the riser has to be retrieved, or if it becomes necessary to disconnect it in severe weather.
7. A marine drilling riser according to any of the preceding claims wherein said cables are steel wire rope or strand, or chains or of lightweight synthetic material construction.
GB0000831A 2000-01-15 2000-01-15 Marine drilling riser Expired - Fee Related GB2358203B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB0000831A GB2358203B (en) 2000-01-15 2000-01-15 Marine drilling riser

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB0000831A GB2358203B (en) 2000-01-15 2000-01-15 Marine drilling riser

Publications (3)

Publication Number Publication Date
GB0000831D0 GB0000831D0 (en) 2000-03-08
GB2358203A true GB2358203A (en) 2001-07-18
GB2358203B GB2358203B (en) 2004-01-14

Family

ID=9883686

Family Applications (1)

Application Number Title Priority Date Filing Date
GB0000831A Expired - Fee Related GB2358203B (en) 2000-01-15 2000-01-15 Marine drilling riser

Country Status (1)

Country Link
GB (1) GB2358203B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007092051A1 (en) * 2006-02-10 2007-08-16 Anadarko Petroleum Corporation System for and method of restraining a subsurface exploration and production system

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1103400A (en) * 1966-10-18 1968-02-14 Shell Int Research Pipestring extending upwardly from the bottom of a body of water
US3996755A (en) * 1975-07-10 1976-12-14 Texaco Exploration Canada Ltd. Tension leg structure with riser stabilization
US4448266A (en) * 1980-11-14 1984-05-15 Potts Harold L Deep water riser system for offshore drilling
US4710061A (en) * 1985-04-12 1987-12-01 Atlantic Richfield Company Offshore well apparatus and method
US4818146A (en) * 1985-01-23 1989-04-04 Texhoma Contractors, Inc. Wellhead and conductor stabilized by a cable and anchor system

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1103400A (en) * 1966-10-18 1968-02-14 Shell Int Research Pipestring extending upwardly from the bottom of a body of water
US3996755A (en) * 1975-07-10 1976-12-14 Texaco Exploration Canada Ltd. Tension leg structure with riser stabilization
US4448266A (en) * 1980-11-14 1984-05-15 Potts Harold L Deep water riser system for offshore drilling
US4818146A (en) * 1985-01-23 1989-04-04 Texhoma Contractors, Inc. Wellhead and conductor stabilized by a cable and anchor system
US4710061A (en) * 1985-04-12 1987-12-01 Atlantic Richfield Company Offshore well apparatus and method

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007092051A1 (en) * 2006-02-10 2007-08-16 Anadarko Petroleum Corporation System for and method of restraining a subsurface exploration and production system
EA013092B1 (en) * 2006-02-10 2010-02-26 Анадарко Петролеум Корпорейшен System and method of restraining subsurface exploration and production system
AP2423A (en) * 2006-02-10 2012-06-13 Anadarko Petroleum Corp System for and method of restraining a subsurface exploration and production system.

Also Published As

Publication number Publication date
GB2358203B (en) 2004-01-14
GB0000831D0 (en) 2000-03-08

Similar Documents

Publication Publication Date Title
US5390618A (en) Offshore mooring system
US5893334A (en) Method and apparatus for mooring floating storage vessels
US5159891A (en) Adjustable boat mooring system for a flexibly-supported tension leg platform
AU742012B2 (en) Riser tensioning construction
US5678503A (en) Method for mooring floating storage vessels
US6893190B2 (en) Method and structure for connecting a floating structure with rope anchor lines to the seabed
US5065687A (en) Mooring system
US4354446A (en) Temporary mooring of tension leg platforms
US4797033A (en) Anchor line-stabilized system
US6216628B1 (en) Semi-weathervaning anchoring system
AU2001291717A1 (en) Method and structure for connecting a floating structure with rope anchor lines to the seabed
US5704307A (en) Taut leg mooring system
US3726247A (en) Mooring system
US6390008B1 (en) Tender for production platforms
GB2200938A (en) System of controlling the position of a body in water
US5566636A (en) Off shore mooring system
US6467423B1 (en) Semi-weathervaning anchoring system
US6408781B1 (en) Mooring system and method for deep and ultra deep water
US6619223B2 (en) Tender with hawser lines
US20070212170A1 (en) Method and apparatus for reducing set-down of a tension leg platform
GB2358203A (en) Marine drilling riser system
US6685519B1 (en) System for transferring fluids and methods for installing, modifying and operating system
JPH10204850A (en) Mooring facility
EP0878389B1 (en) Semi-weathervaning anchoring system
US6575111B2 (en) Method for tendering

Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee

Effective date: 20090115